The Federal Bureau of Prisons has banned Ethan Brown's controversial book Snitch: Informants, Cooperators & the Corruption of Justice, AllHipHop.com has learned.

The 273-page- book was banned when Brown attempted to send a copy to incarcerated former drug lord Kenneth "Supreme" McGriff, who is being housed at The USP Florence Admax Prison in Florence, Colorado.

McGriff was one of the subjects of Brown’s 2005 book Queens Reigns Supreme: Fat Cat, 50 Cent, and the Rise of the Hip Hop Hustler.

"The publication has been rejected because it contains information about other Bureau of Prisons incarcerated individuals," the letter stated. "This information has been determined to be detrimental to the security, good order and discipline of the institution. Due to the reasons cited, the above-named publication is not suited for introduction into a correctional facility."

Brown tackles a number of topics in Snitch, including the 1994 shooting of Tupac Shakur at the Quad Recording Studios.

In a chapter in the book, Brown claims that Walter "King Tut" Johnson was falsely implicated by informants in the infamous Quad shooting.

While King Tut was actually indicted by the feds for committing a string of armed robberies in the mid-1990's, Brown claims that the feds wrongly believed that King Tut was behind the Quad shooting and Shakur’s murder in Las Vegas.

FBI agents hoped to get King Tut to cooperate in the Shakur case by hitting him with federal charges.

Snitch also reveals that during the Spring of 2005, FBI agents attempted to get King Tut to cooperate in an investigation into leading Hip-Hop executives, which was recently described in Chuck Phillips' recent Los Angeles Times article as a "broad investigation of the rap business."

According to Brown, King Tut refused to cooperate in the investigation after NYPD detectives attempted to question him.

King Tut, who has the dubious distinction of being the first New York resident to be sentenced to life in prison under the Federal Three Strikes Provision, denied that he was involved in Shakur's shooting in Snitch.

Tupac named checked King Tut on the song "Against All Odds," where he rhymed:

"Now you gotta watch your back/now watch your front/Here we come/gunshots to Tut, now you stuck.."

"I can understand why the Tupac fans would not like me and I respect their loyalty to him," King Tut said. "But I want the Tupac fans to know that I'm not responsible for his attempted assassination, nor did I have anything to do with his assassination…I'm coming to the public and I'm sacrificing myself. Find me guilty if I'm wrong. Prosecute me to the fullest degree of the law possible if I'm guilty. But if you got an innocent man lying in jail…"

King Tut is currently incarcerated at Lewisburg Penitentiary in Pennsylvania, where he is serving life without the possibility of parole for other crimes.